This is part of the efforts to remove pip-and-virtualenv from our base
images [1].
There are some users who specifically require the virtualenv command
(perhaps, like dib, they have some code that uses the activate_this.py
mechanisms it provides wich venv does not).
This installs the virtualenv package for the currently running
distribution.
One of the main maintenance issues of pip-and-virtualenv is that tried
to ensure that "virtualenv" created a Python 2 environment always by
default. Now that we have Python 3 only distributions like current
Fedora, this is not something we can continue to do (even if we wanted
to, which we don't).
What owns virtualenv and what it produces in our heterogeneous
environment is messy, and I think the best we can do is document it as
done here.
[1] https://docs.opendev.org/opendev/infra-specs/latest/specs/cleanup-test-node-python.html
Change-Id: I97d8bfb970ed2b5aaa02a0813899014c94994066
08bbd16c52